Solar cells are photovoltaic components for direct generation of electrical current from sunlight. Due to the growing demand for clean sources of energy, the manufacture of solar cells has expanded dramatically in recent years and continues to expand. Various types of solar cells exist and continue to be developed. Solar cells include absorber layers that absorb the sunlight that is converted into electrical current. The quality and performance of the absorber layer is therefore of paramount importance. The composition, structure, and integrity of the absorber layer materials are critically important in the solar cell. In order to maximize the efficiency of electrical current production, the absorber layer must be resistant to degradation.
One particularly popular type of absorber material is a CIGS-based absorber material. CIGS—copper indium gallium selenide, Cu(In,Ga)Se2—is a popular chalcogenide semiconductor material and CIGS-based materials find use in various applications, but are particularly useful and favored as absorber layers in solar cells.
Solar cells are encapsulated to protect them from the outdoor environment and to prevent degradation of the solar cell materials. The encapsulation process typically involves laminating an encapsulating film on the solar cell. The lamination process involves high temperature processing and often creates power loss in the solar cells, commonly referred to as LIPL—lamination induced power loss. LIPL is also indicative of a decrease in efficiency of the solar cell such as when a given amount of sunlight produces less electrical current and therefore less power. It is generally believed that LIPL is often attributable to a degradation of the sheet resistance of the absorber layer. CIGS-type solar cells are particularly vulnerable to lamination induced power loss which has been known to produce a power loss ranging from about 8% to about 15% and which undermines CIGS-type solar module performance considerably. Attempts at mitigating LIPL have generally been directed to focusing on the encapsulation, i.e. lamination process itself, but such efforts have been ineffective and may sacrifice the reliability of the encapsulation.
Methods for laminating solar cells without inducing power loss are needed.